Four siblings of a brutally slain Upper East Side psychiatrist suffered through a courtroom screening of the schizophrenic killer’s confession video today — straining to hear as the madman on the screen mumbled, “I would never hurt anybody!”

“I’m sorry! I’m sorry for that woman,” David Tarloff, 41, told cops on the tape, referring to victim Kathryn Faughey, who he admits slashing to death with a meat cleaver in a random attack at her East 79th Street offices in February, 2008.

“It’s so hard to be sitting through this, and seeing him,” Faughey’s eldest brother, Kevin said afterward. “But it’s just something we’re going to have to do,” he said of the sad case, which may go to trial later this month.

Tarloff may have insisted on tape that he’s really harmless, but Manhattan Supreme Court Justice Edward McLaughlin wasn’t taking any chances. When Tarloff asked for a pen, the judge said no.

“Tomorrow we’ll have crayons for you — but not pens and pencils,” he said referring to the ongoing pretrial hearings.